I have only been to DLP but have been looking on the websites of the other parks to find out which rides Paris needs.
They need a kid-friendly roller-coaster (like The Barnstormer or Gadget's Go Coaster) as Casey Jr doesn't really count.
Jungle Cruise as we are the only park that doesn't have one and when the movie comes out it will be very popular.
Possibly a Winnie The Pooh dark ride as now that the show is gone all we have is a meet and greet and a presence in the parade, which doesn't seem good enough when this is a character which is very popular with young children.
Something Monsters Inc. themed for the studios.
Soarin' but possibly over Europe so you can the have the Eiffel Tower and the Leaning Tower Of Pisa.
Some kind of interactive game thing (like sorcerers of the magic kingdom and agent p's world showcase adventure).
Star Tours needs to be upgraded (but that will come with time).
Toy Story Midway Mania would be good!
A new stunt show (like the Indiana Jones one but themed to something more recent (probably Marvel))
A new Muppet 3D show themed around the recent movie (or sequel).
Winnie the Pooh or the little Mermaid dark rides def!!
Splash Mountain would be amazing too :D!
But most of all I would like a new show :)!